Lemon Gelati

Heat sugar and 2 cups water in a small saucepan over low heat, stirring, for 5 minutes until sugar dissolves. Bring to the boil and simmer, uncovered, for 10 minutes or until syrupy. Remove from heat and allow to cool. Stir in lemon juice. Pour mixture into a slice pan and place in freezer until just frozen. Transfer to a food processor or bowl, add eggwhites and process or beat with electric mixer until combined. Return to pan and refreeze until just frozen. Process or beat mixture again, then refreeze until firm.